Preheat the oven to 325°. In a saucepan, melt the butter. Cook over moderate heat, stirring, until the butter is golden brown, about 8 minutes; strain into a glass measuring cup. Reserve the browned butter solids for the Brown Butter Custard Pie.

Pour half of the melted butter into a bowl. Add the sugar, salt, cinnamon and bread, and toss. Spread the bread on a baking sheet and bake for 35 minutes, stirring once or twice, until golden. Let cool.

Rewarm the remaining butter; pour into a food processor. Add the croutons and pulse to fine crumbs; spoon the crumbs into a 10-inch pie plate. Refrigerate for 5 minutes. Press the crumbs over the bottom and sides of the pie plate; refrigerate the crust until chilled, 15 minutes.

Make the Brown Butter Custard Filling

In a microwave-safe bowl, sprinkle the gelatin over 2 tablespoons of water and let stand until softened, 3 minutes. Microwave at high power for 10 seconds, until melted. In a microwave-safe measuring cup, microwave the reserved brown butter solids with the milk, sugar, ⅛ teaspoon of the cinnamon and a pinch of salt until warm. Whisk in the gelatin and refrigerate until set.

In a bowl, whisk ¾ cup of the heavy cream and sour cream to soft peaks. Whisk the custard to loosen it, then fold into the whipped cream. Pour the custard into the Cinnamon Toast Crumb Crust; refrigerate for 30 minutes.

Make the Sweet Potato Ganache

In a microwave-safe bowl, melt the white chocolate and butter. Add the mashed sweet potatoes, the remaining 2 tablespoons of heavy cream and ⅛ teaspoon of cinnamon and a pinch of salt; whisk until smooth. (I did this over a double boiler aka bowl over pot with simmering water)

My change - Spoon the sweet potato ganache over the pie and spread it evenly with the back of a spoon or an offset spatula. Refrigerate until set, at least 30 minutes. Cut the pie into wedges and top each slice with a spoonful of cranberry sauce (if desired).